DEC. 28, 1916. FISHES OF PANAMA MEEK AND HILDEBRAND. 313 



rounded, not much longer than interorbital width; origin of anal slightly 

 in advance of gill-opening, its longest rays equal to or a little shorter 

 than snout; pectoral fins equal to half length of head. 



Color uniform brownish, without dark punctulations; a very distinct 

 yellowish stripe on median line of snout and back, disappearing at origin 

 of dorsal filament. Fins unmarked. 



Of this species only a single specimen was secured, measuring 126 

 mm. in length. It was taken in the Rio Grande, tributary of the Rio 

 Tuyra, several miles above Cana. Several others were seen, floating 

 down stream after a discharge of dynamite, but before they could be 

 reached they had apparently recovered from the shock and quickly 

 disappeared. 



We compared our specimen with several from the Rio Cauca, at 

 Cali, Colombia, and found them to be identical. 



Order III. Haplomi. 



THE PIKE-LIKE FISHES. 



Body elongate; scales cycloid, extending on head; lateral line 

 wanting; fin rays soft; dorsal fin single, placed posteriorly; ventral fins 

 abdominal. Opercles well developed; mesocoracoid absent; hyper- 

 coracoid and hypocoracoid separate; pharyngeal bones distinct. 



Family VIII. Poeciliidae. 



THE KILLIFISHES. 



Body oblong to more or less elongate; depressed anteriorly, com- 

 pressed posteriorly, covered with rather large cycloid scales; head usually 

 flat above; mouth protractile, bordered above by the premaxillaries; jaws 

 with teeth, incisor-like to villiform; gill -membranes more or less con- 

 nected, free from the isthmus; gill-rakers short and thick; dorsal fin 

 single, of soft rays only; ventral fins abdominal; caudal fin usually 

 rounded or truncate. 



The species of this family are very numerous; some of them are 

 viviparous. Those which occur in the area under consideration in 

 this work are all viviparous, except the ones belonging to the genus 

 Rivulus. 



Mr. Regan of the British Museum has lately revised the subfamily 

 PoeciliincB, basing his classification of the genera on the modified anal 



